P26A2
Exhaust Aftertreatment Glow Plug Circuit High
The aftertreatment glow plug current is above expected. Internal short reduces resistance. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Symptoms
- Glow plug warning light on (often orange coil symbol)
- Hard cold start or no start in cold weather
- White smoke from exhaust during warm-up
Common causes
Ordered by how often each turns out to be the cause.
- Internal short in the glow plug elementCommon
- Supply voltage above specificationLess likely
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Aftertreatment Glow Plug
P26A2 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.